Forget the digital chaos for a moment. The most elegant technique for creating a perpendicular requires just one tool: a simple piece of string or a compass. Yes, a compass—the kind you last touched during a math class while doodling in the margins.
This method is called the “classic compass construction,” and it’s been around since before Pythagoras was a glint in his father’s eye. It works because a line drawn from the midpoint of a circle’s chord is always precisely 90 degrees to the tangent. It’s nature’s way of keeping things balanced.
Practical Tip: If you don’t own a compass, use a piece of string tied to a pencil. Anchor the string’s end on your line, draw a semicircle, and repeat from another point. The intersection reveals your perpendicular.
